Scripts — where code lives and runs

In the last lesson you made a script print a message. That script was a tiny list of instructions that Roblox read once, from top to bottom, when the game started. That's all a script is.

This lesson is about where scripts live and which one runs where — because Roblox is not one computer running your game. It's two.

#Every Roblox game is two programs

When someone plays your game, there are actually two copies of the game running:

1. The server — runs on Roblox's computers. It's the official, trustworthy copy. It decides what's really true in the game.
2. The client — runs on the player's own computer. It's what they see and control. It sends the player's clicks and presses to the server.

That's why there are two kinds of scripts:

#Reading a script top to bottom

Scripts execute top to bottom, one line at a time. This script:

local part = workspace.Baseplate

print("Found the baseplate")

part.Anchored = false

means: grab the baseplate, tell me when you've done it, then let it fall. Order matters — if you wrote part.Anchored = false before defining part, the script would error, because it doesn't know what part is yet.

#Finding things: workspace and script.Parent

Look at this line:

local part = workspace.Baseplate

• workspace means the Workspace folder (remember: the game world).
• .Baseplate means "the object inside it named Baseplate".

So this line reads: "get the object named Baseplate, which lives in Workspace, and call it part."

There's another way to find things that matters a lot: a script can look at its own place in the world.

local parent = script.Parent

script is a script's name for itself, and script.Parent is whatever folder or object that script is sitting inside. Developers use this constantly — the script moves with its parent and always finds what it's attached to.

#Where to put scripts

A Script in ServerScriptService runs when the game starts. A LocalScript in StarterPlayer > StarterPlayerScripts runs for each player.

For the rest of this section, put everything in ServerScriptService unless a lesson says otherwise — it keeps server code and client code separate, and you'll build from there.

-- find your own parent

#Common mistakes

• Putting a LocalScript in ServerScriptService. A LocalScript there runs, but on the server, where it has no player to work with. Keep them in their proper folders.
• Expecting a script to run twice. A Script in Workspace runs once per server, not once per player. If you want code that runs for every player, you'll learn the PlayerAdded event later.
• Misspelling what you're looking for. workspace.Baseplat errors. The Output tells you exactly which line — believe it.

Next up: making scripts remember things with variables.